Python on Fedora: venv, pipx, uv and domestic mirrors

python3 -V
rpm -q python3

Python 3.15.0rc1
python3-3.15.0~rc1-1.fc45.x86_64

Fedora’s Python lives in /usr and sys.prefix is /usr — it is a system component, and dnf itself depends on it.

One iron rule

Never run sudo pip install. Not out of taste:

• it writes into /usr/lib/python3.15/site-packages, mixing with rpm-managed files
• dnf upgrade may overwrite or fail on the conflict
• it damages the system toolchain itself (dnf5 is written in Python)

Use one of the three isolation layers below instead.

Layer 1: venv (per-project dependencies)

mkdir -p ~/proj && cd ~/proj
python3 -m venv .venv
source .venv/bin/activate
pip install requests

which python

/home/labuser/proj/.venv/bin/python

Leave with deactivate.

venv isolates packages only; the interpreter is still the system 3.15. That covers most projects.

Tip

Inside a venv pip install needs no sudo, installs into .venv/lib/python3.15/site-packages, and deleting the directory is a complete uninstall.

Pointing pip at a domestic mirror

Configuration precedence: project pip.conf < user ~/.config/pip/pip.conf < global /etc/pip.conf.

mkdir -p ~/.config/pip
cat > ~/.config/pip/pip.conf <<'EOF'
[global]
index-url = https://pypi.tuna.tsinghua.edu.cn/simple
EOF

Verify:

pip config list

global.index-url='https://pypi.tuna.tsinghua.edu.cn/simple'

For a one-off, use -i:

pip install -i https://pypi.tuna.tsinghua.edu.cn/simple requests

Whether the mirror is actually faster depends on your link; see domestic mirrors for how to measure.

Layer 2: pipx (CLI tools)

Some packages are applications, not libraries (black, httpie, ansible). They need their own environment or they fight with project dependencies:

sudo dnf install pipx
pipx ensurepath
pipx install black
black --version

pipx list shows each tool’s isolated environment; pipx upgrade-all upgrades them together.

Layer 3: uv (a different interpreter)

Fedora’s default is one Python (python3 = 3.15.0rc1), but the repo does ship versioned packages. Measured:

sudo dnf install python3.13 python3.14
python3.13 --version   # Python 3.13.15
python3.14 --version   # Python 3.14.7
python3 --version      # Python 3.15.0rc1

All three coexist under /usr/bin/. See multiple versions for the full matrix.

For anything older (3.12 and earlier), or when you need more control:

curl -LsSf https://astral.sh/uv/install.sh | sh

uv python install 3.12
uv python list
uv venv --python 3.12

uv manages interpreter downloads in its own cache and never touches the system Python. pyenv works too:

curl https://pyenv.run | bash
pyenv install 3.12.7
pyenv global 3.12.7

Choosing between them

Need	Use
project dependencies	venv
CLI tools (black/httpie/ansible)	pipx
another interpreter version	uv or pyenv
a fully separate system	containers (see containers)
pinned versions in CI	container images

Common traps

Symptom	Cause
pip: command not found	pip not installed; use python3 -m pip or dnf install python3-pip
error: externally-managed-environment	Fedora blocking writes to system site-packages — exactly why venv exists
ModuleNotFoundError for something you installed	installed into another interpreter or venv; check which python
commands missing inside a venv	forgot source .venv/bin/activate
system tools report Python errors	a past sudo pip polluted system packages; check with rpm -V python3-libs

Related pages

• Multiple versions — python3.13/3.14 parallel packages and the policy per package
• Domestic mirrors — pip mirrors with measurements
• Containers and rootless — full isolation
• Toolchain and multiple versions — the overall strategy
• Official: Python